Failed to delete selected object(s) Insufficient permissions, when deleting a relationship class

Error Message

Attempts to delete a Relationship Class in ArcCatalog may result in the following error:

Code:
Delete Failed
Failed to delete selected object(s)
Insufficient permissions[
Locked by database user: '<username>' on machine: '<machine name>']

Cause

This error occurs under the following circumstances:

1. The owner of the relationship class does not own all of the related objects.

2. The owner of the relationship class has only SELECT privileges on the related objects that they do not own, but not UPDATE, INSERT, and DELETE.

Solution or Workaround

1. In ArcCatalog, connect to ArcSDE as the owner of the related objects.
2. Right-click on the object and choose 'Privileges'.
3. Type in the name of the owner of the Relationship Class in the top of the Privileges dialog box.
4. Check the boxes for SELECT, UPDATE, INSERT, and DELETE.
5. Click OK to dismiss the dialog box.
6. The owner of the Relationship Class should now be able to delete it.